The VVT Solenoid improves gas mileage by controlling the amount of intake and exhaust valve overlap.
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Most VVT Solenoids fail or do not function properly because of oil sludge or oil contamination. The sludge hinders flow through valve screens and causes the solenoid to function incorrectly.
Using the correct oil and following strict oil change schedules will increase the life of a VVT Solenoid
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